Hey James, Funny you should post this. I have been searching for some blank covers in a bronze color. Standard 4" rectangular. I'll let you know if I run across anything like the stainless one you are looking for in my searching. Octagonal shape might be tricky though.

Looks like we are going to have to get some made. Cannot find any stainless steel cover plates in production. If you ever find some, post a link here. I am sure I cannot be the only one out there who needs them.